{"id":"CVE-2026-40190","sourceIdentifier":"security-advisories@github.com","published":"2026-04-10T20:16:24.043","lastModified":"2026-10-26T21:10:00.170","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. Prior to 0.5.18, the LangSmith JavaScript/TypeScript SDK (langsmith) contains an incomplete prototype pollution fix in its internally vendored lodash set() utility. The baseAssignValue() function only guards against the __proto__ key, but fails to prevent traversal via constructor.prototype. This allows an attacker who controls keys in data processed by the createAnonymizer() API to pollute Object.prototype, affecting all objects in the Node.js process. This vulnerability is fixed in 0.5.18."},{"lang":"es","value":"Los SDK de cliente de LangSmith proporcionan SDK para interactuar con la plataforma LangSmith. Antes de la versión 0.5.18, el SDK de JavaScript/TypeScript de LangSmith (langsmith) contiene una corrección incompleta para la contaminación de prototipos en su utilidad lodash set() vendida internamente. La función baseAssignValue() solo protege contra la clave __proto__, pero no logra evitar el recorrido a través de constructor.prototype. Esto permite a un atacante que controla claves en datos procesados por la API createAnonymizer() contaminar Object.prototype, afectando a todos los objetos en el proceso de Node.js. Esta vulnerabilidad se corrige en la versión 0.5.18."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"langchain-ai","product":"langsmith-sdk","versions":[{"version":"< 0.5.18","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","baseScore":5.6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"LOW"},"exploitabilityScore":2.2,"impactScore":3.4},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-13T16:13:33.168377Z","id":"CVE-2026-40190","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-1321"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:langchain:langsmith:*:*:*:*:*:node.js:*:*","versionEndExcluding":"0.5.18","matchCriteriaId":"7304E366-AE7C-45DB-BD8A-77742DB3B235"}]}]}],"references":[{"url":"https://github.com/langchain-ai/langsmith-sdk/security/advisories/GHSA-fw9q-39r9-c252","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory","Mitigation"]}]}